Background
Sudden cardiac death (SCD) is a significant cause of mortality worldwide, posing diagnostic challenges, especially within forensic medicine. Many cases of SCD are only identified post-mortem, often during autopsy, highlighting the complexities of recognizing undiagnosed cardiac conditions (Tavora et al. 2012; Mu et al. 2017). Among the causes of SCD, arrhythmogenic right ventricular cardiomyopathy (ARVC) has emerged as a frequently underdiagnosed condition, attracting increasing attention in recent years (Mu et al. 2017). Expanding knowledge of left ventricular (LV) involvement has led to the reclassification of ARVC into a broader spectrum termed arrhythmogenic cardiomyopathy (ACM), which encompasses right ventricular (RV), left ventricular (LV), or biventricular involvement (Miles et al. 2019; Haines et al. 2024). Currently, ACM is categorized into three primary phenotypes: (1) Dominant-right variant (the original ARVC phenotype): Characterized by predominant RV involvement without significant LV abnormalities. (2) Dominant-left variant (arrhythmogenic left ventricular cardiomyopathy, ALVC): Marked by LV involvement with minimal or no RV abnormalities. (3) Biventricular variant: Involves both ventricles and presents the highest risk for SCD (Corrado and Basso 2022; Tadros et al. 2023; Kodali et al. 2024).
ACM is a relatively under-recognized and diagnostically challenging myocardial disorder characterized by fibrofatty replacement of one/both ventricles. While the right-dominant form of ACM has been more extensively described, biventricular involvement remains insufficiently documented in forensic literature, particularly in the context of SCD without prior clinical manifestations (Luna-Alcala et al. 2024).
This pathological alteration in ACM creates an arrhythmogenic substrate, which is the hallmark feature of ACM, often manifesting as ventricular arrhythmia that may even precede detectable structural changes. Clinical manifestations vary widely, from being entirely asymptomatic to severe life-threatening arrhythmias, with SCD potentially serving as the initial manifestation of an otherwise silent underlying pathology (Augusto et al. 2018; Belhassen et al. 2020; Corrado et al. 2020; Corrado and Basso 2022; Brás et al. 2023; Lin et al. 2023; Cianci et al. 2024).
Despite its severity, ACM is challenging to diagnose. Notably, the biventricular phenotype of ACM is characterized by an elevated risk of SCD and frequently manifests without preceding clinical symptoms, increasing the likelihood of first manifestation being fatal (Migliore et al. 2021; Lin et al. 2023).
In the absence of clear diagnostic markers, the diagnosis of ACM, particularly in forensic contexts, often depends on a detailed post-mortem examination. Histological analysis is crucial to detect fibrofatty myocardial replacement, as a definitive diagnosis (Mu et al. 2017). Recent diagnostic advancements included the 2020"Padua criteria,"which offer a detailed and systematic approach for diagnosing ACM by integrating diverse diagnostic parameters, particularly for biventricular and left ventricular variants (Ouartassi et al. 2023; Brás et al. 2023). For biventricular ACM, the Padua criteria enable diagnosis based on phenotypic features (morpho-functional ventricular abnormalities and/or structural myocardial tissue alterations) without genetic testing, whereas isolated LV phenotypes, such as ALVC, necessitate genetic confirmation due to overlap with other conditions (Ouartassi et al. 2023).
The genetic basis of ACM often involves mutations in genes responsible for cardiac desmosomes, structures critical for cell adhesion within the heart muscle. These genetic mutations, combined with environmental factors, contribute to the progression of the disease (Corrado et al. 2017; Cadrin-Tourigny et al. 2021; Gerull and Brodehl 2021). While most familial ACM cases follow an autosomal dominant inheritance pattern, and competitive sports are known to accelerate disease progression, ACM can still manifest with life-threatening arrhythmias or result in SCD in individuals without a family history or prior engagement in intense physical activity (Brás et al. 2023; Haines et al. 2024).
Due to the complexities that surround ACM diagnosis, it is important to increase the awareness of ACM as a possible cause of SCD, further being better identified will help in accurate diagnostics, and assess risks to the family in the future.
National forensic data support the scarcity of ACM. For example, Fnon and Hassan (2016) analyzed 535 cases of SCD from January 2010 till the end of December 2014 and found that only 4.1% were attributed to cardiomyopathies. Of those, three cases (14%) were diagnosed as ARVC, with only one exhibiting biventricular involvement (Fnon and Hassan 2016). Furthermore, a more recent investigation by Ali et al. (2023), analyzing 246 cases of SCD and sudden cardiac arrest (SCA) from a registry of 5,000 arrhythmia patients over a 10-year period from January 2010 till January 2020, found that just 5.7% were attributable to ARVC, again with minimal representation of biventricular forms (Ali et al. 2023). To our knowledge, published reports of autopsy-verified biventricular ACM in Egypt are scarce. This case underscores the importance of recognizing ACM, including biventricular ACM as a potential cause of SCD in forensic investigations, particularly in regions where awareness and reporting remain limited. The geographic and contextual specific details add real significance to the forensic literature and are valuable given the relative scarcity in this region.
Accordingly, this case report aims to highlight the forensic significance of biventricular ACM as an underrecognized cause of SCD, particularly within the Egyptian context. Specifically, the report aims to address the following key questions: (1) Does this autopsy-confirmed case of biventricular ACM demonstrate histopathological features that align with internationally established diagnostic criteria? and (2) Does this case illustrate the diagnostic value of forensic autopsy in identifying underreported causes of SCD, such as biventricular ACM, within the Egyptian context?
Case presentation
A 50-year-old man unexpectedly collapsed and became unresponsive in a public setting shortly after being involved in a physical altercation. According to witnesses, the man had been engaged in a brief struggle moments before losing consciousness. Emergency services were called right away and cardiopulmonary resuscitation (CPR) was initiated without delay. Despite these efforts, he was declared dead upon arrival at the emergency department. Because of the sudden and unexpected nature of his death, combined with its occurrence during a physical confrontation, the case was reported to the police for further investigation.
He was previously asymptomatic and apparently healthy. There was no noteworthy medical history disclosed. His family history was unremarkable. A medicolegal autopsy was solicited to elucidate the cause of his sudden death.
Autopsy findings
A medicolegal autopsy was conducted at the morgue section of the Egyptian Forensic Medicine Authority (EFMA). The exterior inspection revealed the body of a male of average build. The body was entirely covered with rigor mortis. The corpse was positioned supine with post-mortem lividity evident on the back and dependent regions. No exterior injuries were evident on the body's surface.
On internal examination, the gross examination revealed that the heart was mildly enlarged (450 gm) with a significant increase in epicardial fat (Fig. 1 A). The complete heart was preserved and immersed in 10% formaldehyde for subsequent pathological analysis. The heart was accessed using the short axis technique. Upon sectioning the heart, only the left anterior descending coronary artery exhibited mild stenosis. Transverse cut sections of the heart revealed mild dilatation in both ventricles. The thickness of the right ventricular wall ranged from significantly thin (1 mm) and in some areas to complete absence of the wall in other areas with the fat encroaching the trabeculae. The left ventricular wall thickness was 1.2 cm with notable pale areas and scattered white patches involving the subepicardial region (Fig. 1 B, C, D, E). Other internal organs showed no findings.
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Fig. 1
A The heart exhibits mild hypertrophy, with a noticeable increase in epicardial fat (B) The Gross picture shows the transverse cut section of the heart showing fat encroachment and thinning of the wall of the right ventricle (note the fat infiltrating the wall) (C), (D) Transverse section of the heart shows slight dilatation of both ventricles with fatty infiltration of the whole right ventricle and whitish areas at the subepicardial region of the left ventricle. E The transverse section of the left ventricle shows fatty infiltration in the subepicardial region of the left ventricle
For histopathological examination, multiple specimens were obtained from the coronaries and suspicious areas, encompassing the endocardium, myocardium together with the adjacent pericardium and endocardium, as well as the apex. Histopathological analysis was done using Hematoxylin and Eosin (H&E) staining and Masson trichrome stain which plays a crucial role in differentiating between muscle fibres, collagen fibres, and other tissue components, making it possible to identify and confirm the presence and extent of fibrosis (collagen fibre deposition) in the myocardium (Migliore et al. 2021). Microscopical examination revealed the presence of fibro-fatty tissue replacing myocytes in the right ventricle, reaching trabeculae and transmural in some areas (Figs. 2 A, 3 A), while the left ventricle showed subepicardial fibro-fatty infiltration and scattered fibrotic patches (Figs. 2 C, E and 3 C). The presence of fibrosis was confirmed by Masson trichrome stain (Figs. 2 B, D, F and 3 B). High magnification under the microscope revealed characteristic changes in the myocytes, including evidence of myocyte degeneration, vacuolation and nuclear attenuation (Fig. 3 A, C, D). Additionally, scattered foci of lymphocytic inflammatory infiltrates were observed in the myocardium in both ventricles (Fig. 3 E). Coronaries showed atherosclerosis with non-significant to mild stenosis. Toxicological analyses of the peripheral blood indicated no significant results.
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Fig. 2
A Microscopic pictures show significant fibro-fatty infiltration within the myocardium, with areas of fibrosis (pink-red staining) and adipocytes (clear spaces) replacing normal myocardial muscle fibers of right ventricle. (H&E × 40) (B) Microscopic picture shows significant fibro-fatty infiltration within the myocardium of right ventricle, with collagen fibers (blue) and adipocytes (clear spaces) replacing normal myocardial muscle fibers (red). (Masson trichrome × 40) (C) & (E) Microscopic pictures show significant fibro-fatty infiltration within the myocardium of left ventricle, with areas of fibrosis (pink-red staining) and adipocytes (clear spaces) replacing normal myocardial muscle fibers. The epicardial fat is notably increased with fat infiltration. (H&E × 40) (D) & (F) Microscopic pictures show significant fibro-fatty infiltration within the myocardium of left ventricle, with collagen fibers (blue) and adipocytes (clear spaces) replacing normal myocardial muscle fibers (purple). There are vascular changes surrounded by fibrous tissue, indicative of chronic myocardial remodeling. (Masson trichrome × 40)
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Fig. 3
A Microscopic picture shows significant fibro-fatty infiltration within the myocardium, with areas of fibrosis (pink-red staining) and adipocytes (clear spaces) replacing normal myocardial muscle fibers of right ventricle with evidence of myocyte degeneration. (H&E × 100) (B) Microscopic picture shows significant fibro-fatty infiltration within the myocardium of right ventricle, with collagen fibers (blue) and adipocytes (clear spaces) replacing normal myocardial muscle fibers (purple). (Masson trichrome × 100) (C) Microscopic picture shows significant fibro-fatty infiltration within the myocardium of left ventricle, with adipocytes appearing as clear spaces and fibrous tissue areas appearing as regions of increased eosinophilic staining with evidence of myocyte degeneration. The epicardium shows marked fat infiltration extending into the myocardium. (H&E × 100) (D) Microscopic picture shows cellular details with high magnification revealing characteristic changes in the myocytes, including vacuolation and nuclear attenuation (H&E × 400) (E) Microscopic picture shows significant focal mononuclear (lymphocytic) inflammatory cell infiltrations within the myocardium, perivascular fibrosis, and evidence of myocyte degeneration. (H&E × 100)
Consequently, in the absence of clinical or familial history and without significant ante-mortem clinical data, the diagnosis was made post-mortem, based on a combination of gross pathological and histopathological findings consistent with the established criteria for biventricular ACM and is categorized as a fibro-fatty variant based on the replacement tissue. Specifically, the autopsy revealed a mildly enlarged heart with excessive epicardial fat, and histological examination showed: Fibrofatty replacement of right ventricular (RV) myocardium reaching trabeculae and transmural in some areas. Subepicardial fibrofatty infiltration and scattered fibrotic patches in the left ventricle (LV). Focal lymphocytic infiltration in both ventricles. Alongside the pathogenic hallmarks of ACM, inflammatory infiltrates in the myocardium were notably present in this instance. Criteria for diagnosing ACM, particularly the biventricular form, allows diagnosis based on structural and histopathological features in the absence of genetic data (Corrado et al. 2020; Ouartassi et al. 2023; Brás et al. 2023).
Discussion
ACM is a myocardial condition that may involve one or both ventricles (Corrado and Basso 2022). Data from numerous ARVC registries worldwide emphasize that the disease does not have a specific racial or geographical predilection, supporting its recognition as a global health concern (Elmaghawry et al. 2012; Corrado et al. 2017).
Variations in ACM penetrance and expressivity contribute to a wide variety of phenotypic presentations. Malignant arrhythmias and SCD frequently serve as the initial clinical manifestations, highlighting the complexities of its diagnosis (Haines et al. 2024). Accordingly, precise determination of its prevalence in the general population remains challenging due to its diagnostic complexity. Furthermore, the absence of standardized, large-scale epidemiological data collection continues to limit accurate assessment of its actual burden (Arbelo et al. 2023).
This report discusses a case of sudden death of a previously asymptomatic and seemingly healthy 50-years-old male during a physical altercation. The diagnosis of biventricular ACM was only established during autopsy. The absence of significant medical or family histories emphasizes the diagnostic complexity of ACM, especially in its early phases, which can resemble other cardiomyopathies (Mu et al. 2017; Gerull and Brodehl 2021). ACM typically progresses through three clinical phases. The first phase is the concealed phase, with minimal clinical symptoms and a risk of SCD. The second phase, known as the electrical phase, involves symptomatic ventricular arrhythmias, along with palpitations, syncope, and structural abnormalities. The end-stage phase is the stage of heart failure (Kohela and Van Rooij 2022). Given the absence of prior symptoms and the sudden nature of the death in our case, it is likely that this individual was in the concealed phase of ACM. A previous study indicated that 78% of SCD cases attributed to ACM occur without preceding symptoms or familial risk factors (Miles et al. 2019). Furthermore, as highlighted in this case report of a fatality during a struggle, physical exertion has been identified as a significant risk factor for fatal events, with stressors such as emotional disputes, minor injuries, or psychological stress also contributing to SCD in ACM cases. In response to stress, heightened catecholamine secretion can precipitate life-threatening arrhythmias (Mu et al. 2017). Tavora et al. (2012) found that 56% of SCD cases with ACM were exertional (Tavora et al. 2012).
While no conclusions about sex-related susceptibility can be drawn from a single case, the presented case is consistent with existing literature reporting a higher prevalence of ACM-related SCD among males (Tavora et al. 2012; Ouartassi et al. 2023). Notably, Miles et al. (2019) demonstrated that although ACM affects both sexes, males exhibit a greater tendency towards phenotypic expression, higher mortality, and an increased likelihood of SCA as the initial presentation (Miles et al. 2019). Moreover, although ACM is the most frequent cause of SCD in young adults, its occurrence should not be overlooked in older adults, where the absence of trigger factors may pose significant diagnostic challenges (Tahani et al. 2024).
In this case report, the diagnosis of biventricular ACM was first established during autopsy. Miles et al. (2019) analysed cases of SCD with postmortem diagnosis of ACM and found that 17% involved only the LV, 13% involved only the RV, and 70% showed biventricular involvement (Miles et al. 2019). Similarly, Tavora et al. (2012) demonstrated that ACM most commonly presents with biventricular involvement (Tavora et al. 2012).
Autopsy findings in this case report revealed a mildly enlarged heart weighing 450 g, exceeding the average normal weight for the deceased’s age (380 g) (Saukko and Knight 2016), with a significant increase in epicardial fat. The RV wall showed marked thinning (1 mm to complete absence in some areas), with significant epicardial fat infiltration extending to the trabeculae; normal RV wall thickness ranges from 3–5 mm (Ho and Nihoyannopoulos 2006). The LV wall was 1.2 cm thick, consistent with normal thickness (Walpot et al. 2019) but exhibited pale areas and subepicardial white patches. Miles et al. (2019) highlighted the critical role of histopathological examination during cardiac autopsies in all instances of SCD (Miles et al. 2019). As regards this case report, histologically, the RV showed transmural replacement of myocytes with fibro-fatty tissue, while the LV displayed subepicardial fibro-fatty infiltration with scattered fibrotic patches.
These observations align with the pathological characteristics of ACM, which involve the progressive replacement of myocardial tissue with adipose or fibro-adipose tissue. This process typically begins in the epicardium, advances towards the endocardium, and gradually affects the entire thickness of the ventricular wall, culminating in ventricular wall thinning (Corrado et al. 2015; Cianci et al. 2024; Haines et al. 2024). The insidious progression of ACM underscores the challenges of its early diagnosis (Calkins et al. 2017). Corrado et al. (2015) reported that severe RV thinning and fat infiltration are hallmarks of advanced ACM, often associated with an elevated risk of SCD (Corrado et al. 2015). Our findings are consistent with prior studies, such as those by Sen-Chowdhry et al. (2007), who noted that ACM patients frequently exhibit myocardial hypertrophy and increased epicardial fat (Sen-Chowdhry et al. 2007). Similarly, Migliore et al. (2021) emphasized the diagnostic significance of identifying epicardial fat and fibro-fatty infiltration in confirming ACM (Migliore et al. 2021). DeWitt et al. (2019) described seven cases of ACM characterized by extensive biventricular dilation and wall thinning, with widespread and often transmural fibro-fatty infiltration and fibrosis (DeWitt et al. 2019). Basso et al. (2009) further documented extensive fibro-fatty replacement as a defining feature of ACM, particularly in the RV (Basso et al. 2009).
These histopathological hallmarks result in the encasement of myocardial fibres by non-conductive fatty tissue, causing delayed electrical conduction. This disruption facilitates re-entry phenomena in regions adjacent to intact myocardium, leading to the initiation of ventricular tachycardia (VT). Structurally, the substitution of normal myocardium with fibro-fatty tissue reduces myocardial elasticity, contributing to impairments in both systolic and diastolic function. This compromise in cardiac function results in diminished ejection capacity, which fails to meet myocardial oxygen demands, leading to persistent ischemia and hypoxia (Ban et al. 2024).
The histopathological examination in this case report also revealed distinct myocyte changes, including vacuolation and nuclear attenuation. Scattered lymphocytic inflammatory infiltrates were also observed in the myocardium in both ventricles. The presence of inflammatory infiltrates, although not a consistent feature, has been occasionally observed in ACM, suggesting a possible pathophysiological connection between the disease and inflammation. Research indicates that this inflammatory response may contribute to electrical instability, increasing the risk of ventricular tachycardia and SCD, potentially through the impact of pro-inflammatory molecules on cardiac contractility (Huh 2024). These findings are consistent with those of Sen-Chowdhry et al. (2010), who documented fibro-fatty replacement in the RV of ACM cases, often accompanied by focal inflammatory infiltrates and myocyte degeneration (Sen-Chowdhry et al. 2010). Tavora et al. (2012) reported inflammatory infiltrates in 44% of biventricular ACM cases (Tavora et al. 2012). Furthermore, residual myocytes surrounding areas of fibroadipose degeneration often exhibit features such as partial hypertrophy, atrophy, or vacuolation, along with evidence of coagulative necrosis and predominantly lymphocytic inflammatory infiltrates, highlighting their diagnostic relevance (Cianci et al. 2024).
In summary, the histopathological features observed in this case report including fibrofatty replacement of right ventricular (RV) myocardium reaching trabeculae and transmural in some areas, subepicardial fibrofatty infiltration and scattered fibrotic patches in the left ventricle (LV), focal lymphocytic infiltration in both ventricles, align closely with hallmark characteristics described in the literature and match internationally accepted diagnostic criteria for biventricular ACM, which allows diagnosis based on structural and histopathological features in the absence of genetic data (Basso et al. 2009; Sen-Chowdhry et al. 2007; Corrado et al. 2015; DeWitt et al. 2019; Corrado et al. 2020; Migliore et al. 2021; Ouartassi et al. 2023; Brás et al. 2023; Cianci et al. 2024; Haines et al. 2024). These features suggest that the case is representative of biventricular ACM, while the presence of myocardial inflammation and vacuolated myocytes may reflect known but variably expressed pathological features, rather than uniquely atypical findings (Sen-Chowdhry et al. 2010; Tavora et al. 2012; Cianci et al. 2024; Huh 2024).
This case illustrates the essential role of autopsy as both the first and final opportunity to establish a definitive diagnosis in SCD (Basso et al. 2017). It focuses on the forensic importance of detailed postmortem examination in identifying biventricular ACM, a condition that may remain clinically silent and undiagnosed during life, particularly in the absence of family history. In such contexts, a comprehensive autopsy, including gross and histopathological evaluation, is critical for reaching a definitive diagnosis (Mu et al. 2017; DeWitt et al. 2019; Corrado et al. 2020; Ouartassi et al. 2023; Brás et al. 2023).
Histopathological findings in ACM have been linked to genetic mutations affecting desmosomal proteins. Moreover, ACM predominantly exhibits an autosomal dominant inheritance pattern (Miles et al. 2019; Bradford et al. 2023). Post-mortem genetic testing is a pivotal tool for ACM diagnosis, particularly in cases where phenotypic features are absent (Cianci et al. 2024). In the present case, the diagnosis was based on comprehensive histopathological analysis, which revealed hallmark features of biventricular ACM. These structural abnormalities meet the established diagnostic criteria and are considered sufficient for post-mortem diagnosis in forensic settings. As outlined in recent diagnostic frameworks, the diagnosis of biventricular ACM can be established based on phenotypic features alone, without requiring genetic confirmation (Mu et al. 2017; Corrado et al. 2020; Ouartassi et al. 2023; Brás et al. 2023).
While genetic testing was not undertaken in this case, we fully recognize its growing importance, particularly in supporting familial risk assessment and enabling broader screening initiatives. According to the 2023 European Society of Cardiology (ESC) Guidelines for the management of cardiomyopathies, genetic testing is recommended for a deceased individual with postmortem-confirmed cardiomyopathy if it can guide management of surviving relatives (Arbelo et al. 2023). In this context, the integration of postmortem genetic data (molecular autopsy) has emerged as a valuable tool in both forensic and clinical practice which can support the identification of at-risk family members and enables early diagnosis and early interventions. Genetic evaluation enables the identification of specific genetic variants, which can enhance understanding of disease progression and support more targeted approaches to diagnosis, screening, genetic counseling, and personalized care. As outlined in literature, assessing at-risk family members of the deceased requires a thorough interdisciplinary approach by a cardiologist, clinical geneticist, genetic counselor, and forensic pathologist directly involved with the case (Argo et al. 2012; Goff and Calkins 2019; Aiwuyo et al. 2022; Aiyer et al. 2023; Cianci et al. 2024; Haines et al. 2024; Grubic and Gustafson 2025).
However, in resource-limited settings, access to such testing remains a major barrier to routine application and comprehensive prevention strategies. In the absence of molecular data, ESC 2023 guidelines recommend proceeding with a structured multiparametric clinical evaluation of first-degree relatives. This includes ECG, and cardiac imaging as these may reveal suggestive, though not diagnostic, abnormalities. In cases of ARVC, findings such as “RV systolic global or regional dysfunction, or additional electrocardiographic abnormalities (e.g. repolarization abnormalities, prolonged terminal activation duration, low QRS voltages, frequent ventricular extrasystoles [> 500 per 24 h], or NSVT)” in relatives of a deceased individual with autopsy-confirmed ARVC may warrant close follow-up and further evaluation (Arbelo et al. 2023).
Preventing SCD in patients with ACM presents ongoing clinical challenges and involves a multifaceted approach to their lifestyle and activity habits, medications, procedures, and genetic testing. Given that exercise and extreme physical conditions may provoke fatal arrhythmia, recommendations about restricting high-intensity exercise must be made. In ACM patients deemed at risk, implantable cardioverter-defibrillator (ICD) remains the most effective intervention for preventing SCD. However, there are drawbacks to obtaining an ICD; complications related to the implant, inappropriate shocks, and the burden of ongoing medicines and checks. This highlights the critical need for precise risk stratification to ensure appropriate patient selection for ICD therapy. In addition to ICDs, a range of preventive strategies has been proposed. These include beta-blockers which are often the first-line pharmacological treatment to lower arrhythmia burden, with antiarrhythmic drugs considered if initial therapy fails. For patients with drug resistant arrhythmias or frequent ICD shocks, they may be eligible for an invasive procedure called catheter ablation. Integrating clinical assessments, advanced imaging, and genetic insights can improve risk stratification and guide personalized management, ultimately reducing the burden of ACM-related SCD (Hauer 2018; Goff and Calkins 2019; Corianò and Tona 2022; Polovina et al. 2023; Mistrulli et al. 2024; Grubic and Gustafson 2025).
Conclusion
This case illustrates the diagnostic complexity of SCD in the context of ACM, particularly the biventricular form, which may present without preceding clinical manifestations or contributory family history. The diagnosis in this case was achieved through postmortem histopathological examination, underscoring that in such contexts, a comprehensive autopsy, including gross and histopathological evaluation, is critical for reaching a definitive diagnosis of biventricular ACM. Although the lack of genetic testing and familial follow-up limits the broader clinical and preventive implications of this report, the findings reinforce the forensic relevance of ACM as a differential consideration in cases of unexplained SCD.
This case report draws the attention towards the incorporation of standardized autopsy protocols that include systematic and comprehensive histopathological evaluation in all cases of SCD where no clear cause is identified. Furthermore, it highlights the potential value of developing regional forensic guidelines that consider rare cardiomyopathies such as ACM, particularly in cases presenting without prior clinical symptoms or family history. Such guidelines could also support the integration of postmortem genetic testing, where available, to facilitate the identification of genetic variants. This approach would enhance the diagnostic yield in unexplained SCD and enable more effective risk stratification and implementation of preventive measures in potentially at-risk family members.
Limitations of the study
This case report has several important limitations that warrant acknowledgment. First, postmortem genetic testing was not conducted. While the diagnosis of biventricular ACM was supported by definitive histopathological features, the absence of molecular confirmation limits the ability to identify specific genetic variants associated with the disease. This limits opportunities for genetic testing, personalized risk assessment, and early clinical surveillance in at-risk family members. We highlight this limitation to emphasize the need for increased access to genetic testing, which is critical for comprehensive familial screening and SCD prevention. Second, no ante-mortem clinical data such as electrocardiography (ECG), echocardiography, or cardiac magnetic resonance imaging (MRI), were available due to the unexpected nature of the death. This lack of clinical correlation restricts our ability to compare antemortem functional findings with postmortem observations. Such gaps are a frequent challenge in forensic pathology, particularly in cases of unexplained SCD. Despite this limitation, the histopathological findings remain diagnostically definitive for biventricular ACM. Future investigations should aim to integrate comprehensive clinical assessments, advanced imaging modalities, and postmortem genetic testing when feasible. These approaches, along with family-based screening strategies, are essential to improve diagnostic precision and establish preventive efforts in populations at risk for SCD due to ACM.
Authors’ contributions
The authors make substantial contributions to conception and design, acquisition of data, analysis, and interpretation of data; the authors participate in drafting the article and revising it critically for important intellectual content; the authors give final approval of the version to be submitted.
Funding
The authors declare that there is no funding for this research. This research did not receive any specific grant from funding agencies in the public, commercial, or not-for-profit sectors.
Data availability
No datasets were generated or analysed during the current study.
Declarations
Ethics approval and consent to participate
The study adhered to the Declaration of Helsinki and was approved by the Egyptian Forensic Medicine Authority (EFMA). Anonymous and unidentified data was presented in the study.
Consent for publication
The consent for publishing and presentation of the case report with anonymized data was obtained from the family of the deceased.
Competing interests
The authors declare no competing interests.
Abbreviations
Sudden cardiac death
Arrhythmogenic cardiomyopathy
Arrhythmogenic right ventricular cardiomyopathy
Arrhythmogenic left ventricular cardiomyopathy
European Society of Cardiology
Publisher's Note
Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.
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Abstract
Background
Sudden cardiac death (SCD) is a leading global cause of mortality. Among its etiologies is arrhythmogenic cardiomyopathy (ACM), a relatively under-recognized and diagnostically challenging myocardial disorder characterized by fibrofatty replacement of one/both ventricles.
Case presentation
This study reported a case of a 50-years-old Egyptian male who experienced sudden death during a physical altercation. The absence of significant medical or familial histories highlighted the diagnostic challenges posed by biventricular ACM which in this case was identified only through postmortem examination. Biventricular ACM is a rare myocardial disorder involving both ventricles in which normal myocardial tissue is replaced by fibrofatty scar tissue. Autopsy of the present case revealed a mildly enlarged heart with a notable increase in epicardial fat. Histopathological analysis showed fibrofatty replacement of right ventricular (RV) myocardium reaching trabeculae and transmural in some areas. In the left ventricle (LV), subepicardial fibro-fatty infiltration and scattered fibrotic patches were observed. Focal lymphocytic inflammatory infiltrates were detected in the myocardium of both ventricles.
Conclusion
These findings were consistent with the characteristic pathological features of biventricular ACM. From a forensic standpoint, greater awareness of rare cardiomyopathies such as biventricular ACM among forensic pathologists can enhance diagnostic accuracy. Furthermore, the integration of postmortem genetic testing, where available, can facilitate the identification of genetic variants and enable more effective risk stratification and implementation of preventive measures in potentially at-risk family members.
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Neither ProQuest nor its licensors make any representations or warranties with respect to the translations. The translations are automatically generated "AS IS" and "AS AVAILABLE" and are not retained in our systems. PROQUEST AND ITS LICENSORS SPECIFICALLY DISCLAIM ANY AND ALL EXPRESS OR IMPLIED WARRANTIES, INCLUDING WITHOUT LIMITATION, ANY WARRANTIES FOR AVAILABILITY, ACCURACY, TIMELINESS, COMPLETENESS, NON-INFRINGMENT, MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE. Your use of the translations is subject to all use restrictions contained in your Electronic Products License Agreement and by using the translation functionality you agree to forgo any and all claims against ProQuest or its licensors for your use of the translation functionality and any output derived there from. Hide full disclaimer
Details
1 Forensic pathology Unit, Forensic Medicine authority, Ministry of Justice, Cairo, Egypt
2 Pathology department, College of Medicine, Jouf University, Aljouf, Aljouf, Saudi Arabia (GRID:grid.440748.b) (ISNI:0000 0004 1756 6705)
3 Forensic Medicine and Clinical Toxicology Department, Faculty of Medicine, Suez Canal University, Ismailia, Egypt (GRID:grid.33003.33) (ISNI:0000 0000 9889 5690)
4 Forensic Medicine and Clinical Toxicology, College of Medicine, Jouf University, Aljouf, Saudi Arabia (GRID:grid.440748.b) (ISNI:0000 0004 1756 6705); Forensic Medicine and Clinical Toxicology Department, Faculty of Medicine, Suez Canal University, Ismailia, Egypt (GRID:grid.33003.33) (ISNI:0000 0000 9889 5690)